Filter bag



FIG. 1 is a bottom perspective view of an embodiment of a filter bag;

FIG. 2 is a top perspective view of an embodiment;

FIG. 3 is a front view of an embodiment;

FIG. 4 is a right side view of an embodiment;

FIG. 5 is a rear view of an embodiment;

FIG. 6 is a left side view of an embodiment;

FIG. 7 is a top view of an embodiment; and,

FIG. 8 is a bottom view of an embodiment.

The broken line showing on the filter bag illustrates portions of the claimed design that forms no part thereof. 

CLAIM The ornamental design for a filter bag, as shown and described. 